Center-grinder for lathes.



WNQWNNQ ma 8 I W M M w No. 742,599. PATENTED OCT. 27, 1903.

T. H. GOULTER.

CENTER GRINDER FOR LATHES.

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T. H. GOUL'I ER. CENTER GRINDER FOR LATHES. APPLICATION FILED DEC. 20, 1902. RENEWED SEPT. 3, 19Q3.

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NO MODEL.

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' ATTORNEYS.

UNITED STATES fPatented October 2'7, 1903.

PATENT OFFIC THOMAS H. OOULTER, OF BROOKLYN, OHIO, ASSIGNOR OF ONE-HALF TO GEORGE M. HAYNER, OF DAYTON, OHIO.

CENTER-GRINDER FOR LATH ES.

SPECIFICATION forming part of Letters Patent No. 742,599, dated October 27, 1903.

Application filed December 20, 1902. Renewed September 3. 1903. Serial No. 171,783 (No model.)

To all whom it may concern.-

Be it known that I, THOMAS H. COULTER, of Brooklyn, in the county of Ouyahoga and State of Ohio, have invented a new and useful Improvement in Center-Grinders for Lathes, of which the following is a specification.

My invention relates to that class of lathe attachments which are used for regrinding the small cone projecting from the center of the face-plate of a lathe and commonly known as centers, being the point upon which the work is held while being turned in the lathe. These centers from wear and other causes become in time untrue, so that the apex of the cone is no longer in the true longitudinal axis of the lathe, and they have to be'reground to correct this defect. Devices for doing this work have heretofore been provided which comprehend an emery-wheel mounted upon a suitable frame supported upon the tool-post and having an adjustment that allows it to be laterally moved in a line parallel with the sides of the conical center, said emery-wheel being connected to and driven by gears that are actuated by arms projecting from the faceplate. My invention comprehends these general features, but provides avery simple and convenient construction which is easily and quickly applied to any lathe and is so organized as to get a high speed and an elfective grinding action, as will be hereinafter fully described with reference to the drawings, in

which- Figure 1 is a sectional view of my centergrinder shown applied to a lathe, and Fig. 2 is a similar view of a modification.

In the drawings, A represents the face-plate of the lathe, having the conical center a which is to be reground.

B is a detachable arm rigidly connected to the face-plate, so as to project at right angles to the same or in a direction parallel with the axis of revolution from a point near the outer circumference of the face-plate.

C is the tool-post of the lathe, upon which my attachment is to be supported.

D is a stout bracket-arm firmly clamped to and supported by the tool-post and having a wrist portion 61, upon which is mounted to rotate a crown-wheel E, whose ring of teeth are arranged upon the side of the wheel next to the face-plate of the lathe. On the same side of the wheel E bearing the crown-teeth is arranged a stationary frame D D rigidly fixed to the wrist d of bracket-arm D and supported thereby. One member, D, of this frame lies in the plane of the wheel E and parallel with the same and the other projects in toward the face-plate at an oblique angle.

E is a shaft arranged parallel to the plane of the wheel E and journaled in a bearing in the inner end of arm D of the stationary frame and also in a lug d, projecting from the arm D of the said frame at a point near the outer periphery of the wheel E. This shaft Ehas rigidly keyed upon its outer end a pinion e, that meshes with and derives motion from the crown-teeth of whoel E, and at its inner end, beyond the arm D has a cupshaped bevel-wheel E with teeth on the in-v ner surface of the same. With this cupshaped bevel-wheel there meshes abevel-pinion f, rigidly keyed to a shaft F, which'extends obliquely to the axis of wheel E and is journaled in a bearing in the obliquely-projecting arm D of the stationary frame. This shaft F projects beyond the inner end of arm D of the frame and carries a loose hub G,

on which is rigidly clamped an emery-wheel H. This hub G is mounted on the shaft F, so as to slide thereon, but rotate with it, this being effected by a pin g in the hub entering a longitudinal groove 9 in the shaft F or by other equivalent connection, such as a square shaft or a feather and groove. has a circular groove around it which is embraced by a fork I on an adjusting-rod I The hub G which extends through the arm D of the stationary frame and also through the wrist d of the supporting-arm D. This rod I is provided on its outer end with a knob or handle t', by which the shaft is pushed in and out to cause the emery-wheel H to travel along the end of shaft F. The shaft F sets at an angle 5 to the axis of the rotation of the face-plate of the lathe corresponding to the taper of the cone-face of the lathe-center a.

On the outer circumference of the wheel E is rigidly fixed a projecting pin or lug I, which ICO extends radially outward and is directly in the path of the rigid arm B projecting from the face-plate of the lathe.

The operation of the parts is as follows: \Vhen the face-plate of the lathe rotates, its single rigid arm B strikes the lug or pin Z on the wheel E and causes the same to rotate. The large circle of crown-teeth of said wheel meshing with the relatively small pinion e imparts rapid rotation to shaft E in its stationary bearings, and this speed is further augmented as it is transmitted to shaft F by the relative size of bevel-gears E and f, E being larger than 7". This gives a high speed to the shaft F and to the emery-wheel carried by it, and by adjusting the rod I in or out the emery-wheel is made to traverse the side of the cone of the lathe-center a and grind it with a rapid and true action to a correct contour. The direction of rotation given by the gears to the wheel H is such that wheel H rotates at the grinding-point in a direction reverse to the direction of rotation of the cen ter a, which gives a greatly-increased efficiency for the grinding action.

It will be seen that my grinder requires only one arm B for actuating it from the face-plate, and this arm has a telescopic section B, which permits said arm to be extended to suit the position of the grinding attachment. To accommodate the grinder to various tapers of the center a, the supporting-arm D is simply turned upon the tool-post C to the proper angle, the slight variation in the angle at which arm 13 strikes the pin Z making no practical difference in the working of the attachment.

It will be seen that in my attachment all of the driving-gears are positive toothed gears, and all are arranged on one side of the crownwheel E and between it and the emery-wheel, which gives a most direct, simple, and positively-acting mechanism.

As a modification I may dispense with some of the gear-wheels and drive the emery-wheel bya sleeve t, havinga small pinion p on its end engaging directly with bevel-teeth on a main drive-wheel E as shown in Fig. 2. This is a simpler arrangement,butdoes not give so high a speed for the emery-wheel; but by making the emery-wheel of larger diameter and causing it to move at the grinding-point in opposition to the direction of the center, as shown, good results may be obtained. As in the former case the gears are all positive toothed gears and are all arranged on one side of the main gear-wheel and between it and the emcry-wheel.

Instead of driving the center-guide from an arm projecting from the face-plate of the lathe I may drive my device in the same mannor in which a taper shaft is driven.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. Acenter-grindingattachlnentforlathes,

comprising a main toothed gear-wheel having a tappet lug or pin on its periphery, means forsupporting the said wheel, an emery-wheel with shaft, a stationary frame for holding the shaft of the emery-wheel at an oblique angle to the axis of the main drive-wheel, and an intermediate toothed transmitting-gear arranged exclusively on one side of the main driving-gear and between it and the emerywheel and forming a positively-acting driving mechanism, said main driving-gear being arranged to be rotated by a tappet-arm from the face-plate of the lathe substantially as described.

2. Acenter-grinding attachment for lathes, comprising a main toothed wheel, a wrist for rotarily supporting said wheel, said wrist having a rigid bracket-arm projecting on one side of the main wheel for connection with and support by the tool-post of the lathe, and said wrist having on the other side of the main wheel a stationary framework, and an emery-wheel and toothed gears mounted on said framework on the same side of the main wheel and forming a positive driving mechanism between the main gear and the emerywheel substantially as described.

3. Acenter-grinding attachment forlathes, comprising a main toothed wheel, a wrist for rotarily supporting said wheel, said wrist having an oblique channel-way through the same and a rigid supporting-arm on one side of the toothed Wheel and a rigid stationary frame on the other side of said wheel, an emery-wheel and toothed gears both arranged on the inner side of the main gear, and a sliding adjusting-rod for the emery-wheel extending through the wrist-axis of the main gear-wheel substantially as described.

4. A center-grinding attachment fora lathe consisting of a supporting-frame, a crownwheel having teeth on the inner side, and an emery-wheel and intermediate gears directly and positively connecting the emery-wheel to the crown-wheel, said crown-wheel being provided with a projection adapted to be operated by a tappet action from the face-plate of the lathe substantially as described.

5. Acenter-grinding attachment foralathe, consisting of a stationary and rigid frame, a main toothed gear having a projection from its periphery extending outwardly from the center, an emery-wheel and toothed gears positively connecting the emery-wheel directly to the main toothed gear and lying between the two, and a single tappet-arm for transmitting the power of the face-plate of the lathe to the grinder, the plane of the main gear-wheel and position of the entire rigid frame being made adjustable to various angles to the tappet-arm substantially as and for the purpose described.

6. Acenter-grindingattachmentforalathe, consisting of a stationary frame, a main toothed gear-wheel having teeth on the side ICC and an adjustable emery-Wheel mounted on .the said shaft, all being arranged on the same side of the main gear as described. 10

THOMAS H. COULTER.

Witnesses:

oblique shaft having a bevel-gear on its in- HENRY A. INDOE, ner end meshing with internal bevel-gear, JOHN FIGI. 

